Decay and composition of the hemichordate
            <i>Rhabdopleura:</i>
            implications for the taphonomy of graptolites

Briggs, Derek E. G.; Kear, Amanda J.; Baas, Marianne; Leeuw, J.W. de; Rigby, S. V.

doi:10.1111/j.1502-3931.1995.tb01589.x

Cited by 154 publications

(138 citation statements)

References 26 publications

(32 reference statements)

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“…The primary beam response, the synthesised beam, and the flux density of most sources vary significantly with frequency over the 2 GHz wide bandwidth. One method used to mitigate these issues is to divide (u, v) data into sub-bands and then to force similar beam sizes with an appropriate "robustness" parameter (Briggs 1995). This approach was used to image VLA data spanning 2-4 GHz (Condon et al 2012;Novak et al 2015;Smolčić et al 2015).…”

Section: Imagingmentioning

confidence: 99%

The XXL Survey

Smolčić

Delhaize

Huynh

et al. 2016

A&A

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We present 2.1 GHz imaging with the Australia Telescope Compact Array (ATCA) of a 6.5 deg 2 region within the XXM-Newton XXL South field using a band of 1.1−3.1 GHz. We achieve an angular resolution of 4.7 × 4.2 in the final radio continuum map with a median rms noise level of 50 µJy/beam. We identify 1389 radio sources in the field with peak S /N ≥ 5 and present the catalogue of observed parameters. We find that 305 sources are resolved, of which 77 consist of multiple radio components. These number counts are in agreement with those found for the COSMOS-VLA 1.4 GHz survey. We derive spectral indices by a comparison with the Sydney University Molongolo Sky Survey (SUMSS) 843 MHz data. We find an average spectral index of −0.78 and a scatter of 0.28, in line with expectations. This pilot survey was conducted in preparation for a larger ATCA program to observe the full 25 deg 2 southern XXL field. When complete, the survey will provide a unique resource of sensitive, wide-field radio continuum imaging with complementary X-ray data in the field. This will facilitate studies of the physical mechanisms of radio-loud and radio-quiet AGNs and galaxy clusters, and the role they play in galaxy evolution. The source catalogue is publicly available online via the XXL Master Catalogue browser and the Centre de Données astronomiques de Strasbourg (CDS).

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Section: Imagingmentioning

confidence: 99%

The XXL Survey

Smolčić

Delhaize

Huynh

et al. 2016

A&A

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“…map, a robust weighting scheme Briggs (1995) was applied to the data using a robustness factor of 0.5. The rms noise for the cubes was computed over the channels without emission from M 33 within a galactocentric radius of 8.5 kpc.…”

Section: Hi Surveys Atomic Gas Mass Mmentioning

confidence: 99%

Molecular and atomic gas in the Local Group galaxy M 33

Gratier

Braine

Rodríguez-Fernández

et al. 2010

A&A

144

154

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We present high-resolution large-scale observations of the molecular and atomic gas in the Local Group galaxy M 33. The observations were carried out using the HEterodyne Receiver Array (HERA) at the 30 m IRAM telescope in the CO(2-1) line, achieving a resolution of 12 × 2.6 km s −1 , enabling individual giant molecular clouds (GMCs) to be resolved. The observed region is 650 square arcminutes mainly along the major axis and out to a radius of 8.5 kpc, and covers entirely the 2 × 40 radial strip observed with the HIFI and PACS Spectrometers as part of the HERM33ES Herschel key program. The achieved sensitivity in main-beam temperature is 20-50 mK at 2.6 km s −1 velocity resolution. The CO(2-1) luminosity of the observed region is 1.7 ± 0.1 × 10 7 K km s −1 pc 2 and is estimated to be 2.8 ± 0.3 × 10 7 K km s −1 pc 2 for the entire galaxy, corresponding to H 2 masses of 1.9 × 10 8 M and 3.3 × 10 8 M respectively (including He), calculated with N(H 2 )/I CO(1−0) twice the Galactic value due to the half-solar metallicity of M 33. The H i 21 cm VLA archive observations were reduced, and the mosaic was imaged and cleaned using the multi-scale task in the CASA software package, yielding a series of datacubes with resolutions ranging from 5 to 25 . The H i mass within a radius of 8.5 kpc is estimated to be 1.4 × 10 9 M . The azimuthally averaged CO surface brightness decreases exponentially with a scale length of 1.9 ± 0.1 kpc whereas the atomic gas surface density is constant at Σ H i = 6± 2 M pc −2 deprojected to face-on. For an N(H 2 )/I CO(1−0) conversion factor twice that of the Milky Way, the central kiloparsec H 2 surface density is Σ H 2 = 8.5 ± 0.2 M pc −2 . The star formation rate per unit molecular gas (SF efficiency, the rate of transformation of molecular gas into stars), as traced by the ratio of CO to H α and FIR brightness, is constant with radius. The SFE, with a N(H 2 )/I CO(1−0) factor twice galactic, appears 2-4 times greater than for large spiral galaxies. A morphological comparison of molecular and atomic gas with tracers of star formation is presented showing good agreement between these maps both in terms of peaks and holes. A few exceptions are noted. Several spectra, including those of a molecular cloud situated more than 8 kpc from the galaxy center, are presented.

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“…This image was used to self-calibrate the data. After the selfcalibration and continuum subtraction, image cubes were created using the robust weighting scheme (Briggs 1995) with a robust parameter of zero for all galaxies. These image cubes were then cleaned down to a level of ∼1σ.…”

Section: Data Reductionmentioning

confidence: 99%

The baryonic Tully-Fisher relation and its implication for dark matter halos

Trachternach

Blok²,

McGaugh

et al. 2009

A&A

100

122

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Context. The baryonic Tully-Fisher relation (BTF) is a fundamental relation between baryonic mass and maximum rotation velocity. It can be used to estimate distances, as well as to constrain the properties of dark matter and its relation with the visible matter. Aims. In this paper, we explore if extremely low-mass dwarf galaxies follow the same BTF relation as high-mass galaxies. We quantify the scatter in the BTF relation and use this to constrain the allowed elongations of dark matter halo potentials. Methods.We obtained H i synthesis data of 11 dwarf galaxies and derive several independent estimates for the maximum rotation velocity. Results. Constructing a BTF relation using data from the literature for the high-mass end, and galaxies with detected rotation from our sample for the low-mass end results in a BTF with a scatter of 0.33 mag. Conclusions. This scatter constrains the ellipticities of the potentials in the plane of the disks of the galaxies to an upper limit of 0−0.06, indicating that dwarf galaxies are at most only mildly tri-axial. Our results indicate that the BTF relation is a fundamental relation which all rotationally dominated galaxies seem to follow.

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Decay and composition of the hemichordate Rhabdopleura: implications for the taphonomy of graptolites

Cited by 154 publications

References 26 publications

The XXL Survey

The XXL Survey

Molecular and atomic gas in the Local Group galaxy M 33

The baryonic Tully-Fisher relation and its implication for dark matter halos

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